One of the things learned growing up is that you don't put a Siddur or Chumash on a seat where you sit becuase it is disrepspectful. With that in mind does the same hold for your Talis and Tefilin bag? There is kedusha towards these items as Mishna Berurah points out that you can not throw these items in the garbage after they were used to hold our talis and tefilin.
With those ideas in your mind, my next question is when people go to shul why do they leave their talis and tefilin bags on a seat in front of them or next to them? What if somone wants to sit there? This morning when I got to shul there was a whole row filled with peoples talis and tefillin bags which meant no one could sit there unless these kind people moved their talis and tefilin bags. Why couldn't these people designated one area and pile these bags on top oof each other? Why do these people feel that they can use up all the space in a small synagogue that they want while at the same time taking space away from someone else? To me, these people are selfish and disrespecting the synagogue which is not a storage facility or a place where someone cannot sit because it is being occupied by someones talis and tefilin bag.